[Offline pages] Add new Error page failure status inside the MHTML archiver and update correspondin…

chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc

Index: chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc
diff --git a/chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc b/chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc
index d8560f1e05a4decd9683d68e844ed3399141b3f7..014b04bf839e79673c70f24e27235aa3bfa1e2c3 100644
--- a/chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc
+++ b/chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc
@@ -16,8 +16,10 @@
 #include "chrome/browser/ssl/security_state_tab_helper.h"
 #include "components/security_state/core/security_state.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/mhtml_generation_params.h"
+#include "content/public/common/page_type.h"
 #include "net/base/filename_util.h"
 
 namespace offline_pages {
@@ -63,6 +65,12 @@ void OfflinePageMHTMLArchiver::CreateArchive(
     return;
   }
 
+  if (web_contents_->GetController().GetVisibleEntry()->GetPageType() !=
+      content::PageType::PAGE_TYPE_NORMAL) {

[chili, 2017/04/10 20:27:18]

The error page types are: NORMAL, ERROR, INTERSTITIAL, so this will prevent
saving of interstitial pages as well. Alternatively we can fine-grain this more
with different enums or only keep track of error pages.

[romax, 2017/04/10 21:19:34]

would it be possible that the INTERSTITIAL page is a 'maybe' page rather than an
error page?

[Pete Williamson, 2017/04/11 17:08:50]

Good comment, please add it to the code instead of just the code review.  

By the way, what exactly is an INTERSTITIAL page?  Is it a redirect page, or
something different?

[chili, 2017/04/11 20:40:16]

As the code is currently implemented, that's not very possible. Interstitial
page here means that we detected something potentially bad, and injected an
additional information page in the middle. It's probably not good to download
the page in that instance.

We will track it separately though, to keep an eye on the numbers and confirm
numbers somewhat make sense.

+    ReportFailure(ArchiverResult::ERROR_PAGE);
+    return;
+  }
+
   GenerateMHTML(archives_dir, create_archive_params);
 }